Accelerate LSP Startup by Parsing Only vlib Signatures

[kbkpbot]

​Idea:​​ To significantly improve the V Language Server startup time and responsiveness, we could implement a fast-load mode for the vlib. Instead of fully parsing the entire standard library, the LSP would only process the ​signatures/declarations​ of functions, structs, constants, etc., while ignoring the function bodies entirely.

For example, a function like http.get(url string) ?Response would be parsed for its interface, but its potentially complex implementation body would be treated as empty. This drastically cuts down the number of AST nodes the LSP needs to build and hold in memory.

​Expected Benefits:​​

• ​Faster LSP Initialization:​​ Startup time could be reduced, as the parser skips the majority of the code in vlib.
• Lower Memory Footprint:​​ The AST would be much smaller, making the LSP more lightweight.

[JalonSolov]

This sounds like a good optimization. The function signature is all you're really worried about, unless you're working on the body of the function.

The signature is the only part that matters for hover hints, completions, etc. Well, and doc comments, too.

[medvednikov]

Yes that's the plan.

In fact I had it implemented in original V before the 2020 re-write (.vh headers with just declarations).

[kbkpbot]

Implement in PR #25531

[medvednikov]

Thanks @kbkpbot

Have you measured the speed up?